Spring release hitch



Jan. 13, 1942. J. MoRfKosKl A, 2,269,981 SPRING RELEASEHITGH Original Filed March 26, 1940 2 Sheets-Sheet l @Awww N Jan. 13, 1942. J.- Mon-msm 2,269,981

SPRING RELEASE HITCH Original Filed March 2e, "1940 2 sheets-sheet 2 James fof/os/u .5 PM j Patented Jan. 13, 1942 SPRING RELEASE HITCH James MorkoskL-Canton, Ill., assignor to International Harvester Company, a corporation of New Jersey original application March 26, 1940,` serial No.

326,065. Divided and this application February 1o, 1941, serial No. 378,256

(C1. .esulisaler 6 Claims.

` Thisinvention relates to spring release hitches for the connection of implements to tractors.

This application is a division of the applica- `tion filed by the present inventor on March 26,

1940, Serial No. 326,065, and relating to spring release devices.

The object of the present invention is to provide a spring release hitch for the connection of implements to tractors which is of simple construction and cheap to manufacture in that only minimum parts are required.

It is another object of the invention to provide a novel arrangement in a spring hitch, wherein the same is readily adjustable to different tensions required for the different implements and wherein this adjustment is of simple construction. According to the present invention, use is made of the buckling ability of a coil spring for effecting release of a latching element from locked engagement with a cooperating element. The latch element is pivotally connected to a member which may be the part of either an implement or a tractor, and this latch element has connected to the same a coil spring extending between the same and a base member. This spring isconnected to the pivoted latch member and tothe base member by means of lever elements so shaped as to throw the longitudinal axis of the coil spring offset with the axis of connection of the pivotal elements with the respective pivotal latch andy base members. When excessive strain ris placed upon the latch element, the coil spring, due to its offset connection, will tend to contract along one side and then suddenly buckle to relieve the latch element or the implement. In the present arrangement the release mechanism is carried Iby the pull-behind implement, and the cooperating part is carried by the tractor. It should be evident, however, that the release spring and latch element could as well be carried by the tractor, and the cooperating part could be disposed on the implement.

As a means for adjusting the resisting effectiveness of the buckling spring, there is provided an adjusting screw carried by the base member, the head of which is adapted to contact with the side of the coil spring intermediate its length. As, an initial slight buckling is given to the coil spring by this adjusting means, the force required t nally buckle the coil spring is decreased.

For other'objects and for a better understanding yofthe invention, reference vmay be had to the :following detailed description taken inconnection with the' accompanying drawings, in which:

Figure 1 is a view in elevation of a part of a tractor 'and of a part of an implement with the release being carried by the implement and the same connected to the cooperating element on the tractor;

Figure 2 is an enlarged view of the release device showing in full the position of the vspring while the implement is being drawn and showing in dotted the buckled position of the spring and the pivotedposition of the latch at the time of release of the implement from thel tractor; and,

Figure 3 is a plan view of the forward part of theimplement and of the release devicethere-` 'Referring now to the drawings, there is ,shown a tractorY I0 having a rear axle structure II to which is connected a draw-bar I2 extending rearwardly behind the tractor and adapted for the connection thereto of a pull-behind implement I 3. The pull-behind implement I3 has a draft connection I4 which serves as a base for the connection thereto of the spring release device, indicated generally at I5. Referring particularly to Figure 3, it-will be noted that this draft connection includes one forwardly extending draft or base member I6, a diagonally disposed base member Il, and a transversely extending member I8, to which the rearward -ends of the members I6 and I'l are connected. This transverse member I8 is connected to the draft connection I4 of a frame I9 of the pull-behind implement by the clevis connections 20 and 2 I. In all three of the members I6, I1, and I8, there is provided a set of longitudinally alined holes for the purpose of arranging the respective members in different positions with respect to each other. On the forward end of the base member, as shown more clearly in Figure 2, there is pivoted a latch member 23 having a recess 24 adapted to receive a cooperating element or clevis 25 which is carried on the draw-bar I2 of the tractor. 'Ihe draft member I6 includes upper andlower members I6 and I6". The upper draft member I6 is folded back upon itself at its forward end to provide for the pivotal connection thereto of the latch member 23, as indicated at 2B.

Coming now more particularly to the feature of the present invention, there is pivoted to the upper end of the latch element 23 a pivotal element 21, as indicated at 28. This pivotal element has a threaded portion 29 olset from its pivot axis 28. Rearwardly of the latch element and connected to the base member I6' is a bracket 30 which has pivoted to it a second pivotal element 3l similar to the pivotal element 21. I'his pivotal element 3l also has an offset threaded portion 32 which is offset with respect to the pivotal axis 33 of its connection with the bracket 30. The threaded portions of these pivotal elements 21 and 3| oppose each other and receive a coil spring 34, the ends of which are respectively threaded on the threaded portions 28 and 32. By having the spring ends pivotally connected to the pivotal elements, the spring remains connected to the same regardless of whether the coil spring 34 is in tension or in compression.

When the latch element 23 is in its unreleased position with the cooperating element 25 on the tractor within the recess 24 thereof, the coil spring 34 is in its unbuckled state with the respective coil elements axially alined. An axis through the coil spring when in this position is indicated at A, and it will be noted that this axis is oiset with respect to an axis throughithe pivotal connection of the respective pivotal elements 21 and 3| carried respectively between latch elements 23 and bracket structure 30. The amount of this oiset is more or less immaterial, it being sufficient that there be only the slightest of offset to have the device function to release upon receiving excessive strain.

Immediately beneath the coil spring and in contact therewith is an adjusting screw 35 threaded with the base member I6 and adapted to be iixed in any setting thereof by a locking nut 36. With this adjusting nut the resistive force of the coil spring can be regulated. The adjusting nut may be raised suiciently so as to permit the coil spring to straighten out to its normal position, and in this manner lessen the amount of force required to buckle the same. This adjusting screw works within definite limits and is eiective to vary the resisting tendency of the spring to buckle.

As the strain upon the spring 34 becomes eX- cessive, due to some obstruction met with by the implement I3 being pulled by the tractor I0, the i i latch member 23 will tend to pivot about its pivotal connection 26 with its base member I6 to place a compression force upon the coil spring, and the pivotal elements 21 and 3l being oiiset with respect to the pivotal connection with the f latch and bracket members 23 and 24, compression will take place along the lower edge of the coil spring, thereby permitting the respective coils at their upper edge to leave one another. When this compression of the spring on its lower edge is sui'icient, and due to the buckling characteristic of coil springs, the spring will suddenly buckle to its maximum amount, as shown in dotted in Figure 2. This bucklingof the spring permits the latch element to suddenly rotate in a clockwise direction, as viewed in Figure 2, to allow the cooperating clevis element 25 to release from the recess 24 and to thereby free the implement of the tractor. Once the implement has been freed the latch element 23 will be returned to its original position by the coil spring 34. When the obstruction is removed from the implement, the draft connection can again be connected with the tractor.

It should now be apparent that there has been provided a release hitch device for the coupling of implements to tractors which is of a simple construction and includes a simple means for adjusting same.

While various changes may be made in the detail construction of the arrangement, it is understood that such changes shall be made without departing from the spirit and scope of the present invention as defined by the appended claims.

What is claimed is:

1. In a release hitch device for tractors, a supporting element adapted to be connected to a tractor, a latch element pivoted to the supporting element and adapted for the connection thereto of a hitch member of an implement, a buckling spring, and means for connecting the buckling spring between said two elements normally to resist relative pivotal movement therebetween, but to buckle suddenly upon a predetermined iorce being applied to pivot the latch element with respect to the supporting element, said connecting means including a pivotal member pivotally connected to one of said elements, and said pivotal member having a connecting portion for the spring oiiset with respect to the axis of pivotal connection of the member with the element to insure thereby sudden buckling of the spring.

2. In a release hitch device for tractors, a supporting element adapted to be connected to a tractor, a latch element pivoted to the supporting element and adapted for the connection of a hitch member of an implement thereto when in its normal position for the pulling of the implement, a buckling spring, and means for pivotally connecting the ends of said spring respectively to the supporting element and to the latch element to permit the same to buckle for unlatching of the hitch element of the implement from the latch element when the implement meets with an obstruction, said pivotal connecting means including pivotal members respectively pivotally connected to the supporting and hitch elements, each of the members having a connecting portion for the spring offset with respect to the axis of pivotal connection of the member with the element, whereby the buckling spring will be offset with respect to a line drawn between the pivotal connection of the members with the elements to thereby insure sudden buckling of the buckling spring.

3. In a release hitch device for tractors, a supporting element adapted to be ,connected to a tractor, a latch element pivoted to the supporting element and adapted for the connection of a hitch member of an implement thereto when in its normal position for the pulling of the implement, a buckling spring, means for pivotally connecting the ends of said spring respectively to the supporting element and to the latch element to permit the same to buckle for unlatching of the hitch element of the implement from the latch element when the implement meets with an obstruction, said connecting means including a pivotal member pivotally connected to one of said elements, and said pivotal member having a connecting portion for the spring offset with respect to the axis of pivotal connection of the member with the element to insure thereby sudden buckling of the spring, and adjustable means for varying the effectiveness of the device to resist the unlatching of the latch element.

4. In a release hitch device for tractors, a supporting element adapted to be connected to a tractor, a latch element pivoted to the supporting element and adapted for the connection of a hitch member of an implement thereto when in its normal position for the pulling of the implement, a buckling spring, means for pivotally connecting the ends of said spring respectively to the supporting element and to the latch element to permit the same to buckle for unlatching of the hitch element of the implement from the latch element when the implement meets with an obstruction, said pivotal connecting means including pivotal members respectively pivotally connected to the supporting and hitch elements, each of the members having a connecting portion for the spring offset with respect to the axis of pivotal connection of the member with the element, whereby the buckling spring will be offset with respect to a line drawn between the pivotal connection of the members with the elements to thereby insure sudden buckling of the buckling spring and an adjustable stop means on the suporting element and contacting with the side of the spring between the ends of the same to prevent, if desired, the return of the spring to its normally straight position and thereby to vary the effectiveness of the device to resist the unlatching of the latch element.

5. In combination, a tractor element, an implement element, and releasable hitch means for connecting the two elements together including a latch member pivoted on one of the elements and adapted for locking engagement with the other of said elements, means being provided on the other of said elements for the engagement therewith of a latch member, a buckling spring, and means for connecting the buckling spring between the pivoted latch member and the one of said elements normally to resist pivotal movement of the latch member but to buckle suddenly upon a predetermined force being applied to pivot the latch member and to thereby release the other of said elements, said connecting means including a pivotal member -pivotally connected to one of said elements, and said pivotal member having a connecting portion for the spring oiset with respect to the axis of pivotal connection of the member with the element to insure thereby sudden buckling of the spring.

6. In combination, a tractor element, an implement element, and releasable hitch means for connecting the two elements together including a latch member pivoted on one of the elements and adapted for locking engagement with the other of said elements, means being provided on the other of said elements for the engagement therewith of a latch member, a buckling spring, andmeans for connecting the buckling spring between the pivoted latch member and the one of said elements normally to resist pivotal movement of the latch member but to buckle suddenly upon a predetermined force being applied to pivot the latch member and to thereby release the other of said elements, said connecting means including a pivotal member pivotally connected to one of said elements, and said pivotal member having a connecting portion for the spring offset with respect to the axis of pivotal connection of the member with the element to insure thereby sudden buckling of the spring and adjustable means for varying the eectiveness of the device to resist unlatching of the latch member.

JAMES MORKOSKI. 

